Reminder to home gardeners as spring lawn growth kicks in

Spring has arrived heralding the annual surge in growth of lush garden lawns – and the unwanted return of annoying lawn weeds.

Gardeners who protect their lawns by spraying during spring and summer are reminded to not use the herbicide clopyralid on their lawns.

Agcarm chief executive Mark Ross says that products containing clopyralid were taken off the retail market for home gardeners some years ago, but there is evidence that some are still using old stocks of the chemical on their lawns.

“Clopyralid products are available for agricultural weed control and commercial turf management by qualified approved handlers, but cannot be used on domestic lawns,” he said.

Clopyralid is in a number of products used to control broad-leafed weeds in lawns, sports grounds, golf courses, field crops and forests. It is sold under 20 brand names.

Turf managers at sports fields find it particularly useful against prickly weeds and clover, and because of its low toxicity, fields can be returned to use quickly.

“It is effective and poses little threat to humans when used correctly but it can affect plants grown in composted grass clippings from lawns treated with it,” says Ross.

The Environmental Protection Authority reassessed clopyralid after it was found that domestic use on lawns was affecting composting operations by both local bodies and private companies.

The reassessment resulted in requirements for mandatory labelling of products which warn against composting contaminated clippings.

A label on a typical clopyralid product states clearly ‘Not for use in home gardens’ and ‘Do not use for treating turf that will be mown and the clippings used for making compost; or made available for collection for, or deposited at, a municipal green waste recycling depot’.

The use of Clopyralid on lawns has unintended consequences. Lawn clippings carry the herbicide over into compost which, when applied to gardens, can cause stunting and distortion of growth in susceptible plants.